linux-yocto/4.15: crypto: aes-generic - fix aes-generic regression on powerpc
Integrating the following upstream commit to fix gcc regression:
crypto: aes-generic - fix aes-generic regression on powerpc
commit
6e36719fbe90213fbba9f50093fa2d4d69b0e93c upstream
My last bugfix added -Os on the command line, which unfortunately
caused a build regression on powerpc in some configurations.
I've done some more analysis of the original problem and found
slightly different workaround that avoids this regression and also
results in better performance on gcc-7.0: -fcode-hoisting is an
optimization step that got added in gcc-7 and that for all gcc-7 versions causes
worse performance.
This disables -fcode-hoisting on all compilers that understand the
option. For gcc-7.1 and 7.2 I found the same performance as my previous
patch (using -Os), in gcc-7.0 it was even better. On gcc-8 I could see
no change in performance from this patch. In theory, code hoisting
should not be able make things better for the AES cipher, so leaving it
disabled for gcc-8 only serves to simplify the Makefile
change.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Link: https://www.mail-archive.com/linux-crypto@vger.kernel.org/msg30418.html
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83356
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83651
Fixes: 148b974deea9 ("crypto: aes-generic - build with -Os on gcc-7+")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Kevin Hao <kexin.hao@windriver.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
